paper casting

I purchased a bunch thick sheets used for casting in the 40 and 50’s does any one know how to cast them

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I think what you have is paper pulp, which was/is put up in thick sheets with a rough surface. You’ll need a container of some sort and a way to mix the dried pulp thoroughly with water — for small projects a blender works, but for much larger projects get a paint stirer for use with an electric drill. The molds are typically plaster of paris, I believe, which sucks the water out of the mixture. You can make a plaster mold of an object and cast paper in it repeatedly — the mold can have no undercuts or you will have trouble removing the original. Molded paper objects typically are more like bas-relief than in-the-round sculptures. You pour the beaten pulp into the mold, trying to maintain a uniform thickness of pulp on the mold surface, usually I believe about 1/2 inch thick pulp layer or less.

However, if what you have is mat flong, all bets are off! :-)

Bob

Thanks Bob I probably did not describe what I have effectively. They are sheet about 24 by24 that already have impressions in them my ? Is how would set up to cast them. I am going to give it a try soon I will let you know how it turns out.

They were probably stereotype molds. You would either need a stereotype caster or to build something similar.

Paul

Yes, those are stereotype mats, and you actually need two major pieces of equipment to use them effectively — a stereo caster large enough for that size mat, and a surfacing machine that is used to machine the back side flat, parallel to the printing surface, and the proper thickness for mounting type high. The mats were used by newspapers, which had all the needed equipment for preparing the stereos for printing.

If you just want to cast in them to have a plate, which couldn’t be used for printing very easily without the above, you could make a steel flat pan the size of the mats, with raised edges, lay the mats in the pan on a very flat strong heat-proof surface, heat a bunch of type metal, or just plain lead, and pour it into the mat, trying to prevent the metal from running off the edges and maintaining as smooth and level a surface as you can. When it cools you should be able to peel the mat off and have a casting from it to display.

Bob

AdLib’s method reveals he has probably read a brief descript of a stereo recovery but has never actually reproduced same. :o) Yes, a stereocaster is an essential piece of equipment, but a surfacing machine is certainly not. In most of the smaller shops, bearer bars provided accurate height of the casting. Said bars could easily be machined to allow a printer choice of available wood mount. (Dilettantes notwithstanding, common three-quarter inch ply was most employed) Or, the mats could be cast type high. (Imagine that weight of the 24x24 mats!) And, depending upon one’s agility at trimming said cast, a router could also aid blemish-free cast by reducing shoulders.
The procedure of pouring hot metal onto an open mat reveals also very limited understanding of typemetal or, for that matter, common lead. There is a reason for the amalgam of lead, tin, antimony in typemetal. Each ingredient has specific purpose in producing clean, crisp, sharp image. Look it up. Simply pouring hot metal onto the mat will merely scorch the surface, cool too quickly to allow proper flow - thus inadequate coverage - and should any impression actually reveal, the image will be ‘rounded’ to the point of bare readability. A stereocaster is a heated box, of substantial heft to provide suitable ‘heat sink’, having heat controlled according to typemetal composition, and is not a skill easily mastered. Has anyone wondered why the smaller mats always had a piece of gummed paper tape attached to them? Or how it was a curved stereo (to fit a web press), having minimum distortion, was obtained from a flat forme? :o)
The large size mats described, although I have seen small shops equipped with appropriate-sized manual caster, were more often reproduced via an automatic machine such as those employed by the larger newspapers and typesetting houses.
Should you not have access to proper caster, bobeng, I suggest you shellack the mats, mount them in period frame, them place them in prominent spot on a featured wall. Very attractive, historic, and, properly explained, a source of wonderment to the ‘instant’ ‘puter generation; not to mention the polyplate crowd. :o)
As to those ready to pounce about the use of chalk plates, well, look to those components. :o)

I am pretty familiar with the stereo casting process as it was practiced but I also assumed that someone who had acquired a bunch of mats and didn’t know the terminology also wouldn’t have the necessary equipment, nor access to working examples - I have no idea who has operable stereo casting equipment any more. Actually, I suspect a preferable method for making a cast of the mats might be to coat them with a waterproof coating like varnish or wax, and make casts using plaster of Paris, then paint the casts silver or whatever color. Could paint them silver and roll ink on the surface to highlight to image. Lots of possibilities — but among them I doubt a stereo caster is likely.

Bob

Tom Parsons, who is setting up a letterpress shop in the historic Littleton, Colorado railroad station, just posted some pictures of a shop that was donated to his endeavor:

http://letterpressdepot.us7.list-manage2.com/track/click?u=19578f266db11...

and included in the equipment was a modern, and very nice looking Nolan flat caster, similar to the Hammond Easy Caster, and what appears to be a Vandercook block leveller, and that could be used to surface the backs of cast stereos to type high. Stereotype equipment is around, there’s even a complete setup here in our town in the back shop of what was the newspaper, and if there was some compelling reason a cast had to be made, it can still be done, even the hand poured method AdLib described but with the casting bars securely clamped to his steel backing surface.

Every weekly newspaper printed by letterpress had to make castings every week as they received their national and even regional ads in the form of mats that had to be cast. And there was a yearly mat service that shipped a large box of mats for seasonal material that could be incorporated into advertisements.

I did a time and motion study once in the stereotyping department at the Pittsburgh Post-Gazette and watched on a number of occasions the rolling of mats, getting them ready, and the casting process on automatic casting equipment. Maybe this is all a mystery to people now, but it was once the daily bread and butter of mainly newspaper printing.

Fritz

Hi, I have just purchased an easy caster and a chest full of the shallow mold impressions I think you are describing . The pressman who used it told me the compressed card molds would be taped in the mold cavity in horizontal mode then glamped and up ended under the pouring spout. Whan the lead was at the correct temp ,the tap was opened to fill the mold cavity. It was then allowed to cool and then released. A router was used to back off the lead impression casting for printing which I manage to purchase also. Hope this helps!

Hello, I have a Hammond Flat Caster (5 col.) It was used every week for my weekly paper and still works. You have to tape card stock to the top of the mat so when you pore, the metal will fill the cavity quickly and in about 5 minutes you can open the caster and remove your plate. Then cut up whatever part of it you wish to mount. It is a great way to get artwork and I still have Metro mats from the 70’s. Hope this info is helpful, Bob.